John Mayer admits he was "very, very nervous" to attend the Academy Awards with girlfriend Jennifer Aniston on Sunday. "It's not my world, the Oscar thing," he said on Ryan Seacrest's KIIS-FM radio show Wednesday while promoting his cruise line, the Mayercraft Carrier 2. "You can go from a Grammy winner to a water boy when you walk in the Kodak Theatre on Oscar night," he added. "That's just like a whole different level."

He said he went as "moral support" for Aniston, who presented an award in front of ex Brad Pitt and Angelina Jolie. Although he went there to support Aniston, Mayer said his role soon turned into: "'Will you please introduce me to so-and-so?'" Added the singer, "It was really, really fun."

"As men, we're incredibly sensitive about the decisions that we make with the women that we're with," he went on. "I'm the kind of person who's like: If I'm going out with a friend who's bringing a woman and that friend brings another friend and I have to sit on one side of the table with that other person I don't know, I have a terrible time because I always feel like people look by and go, 'Oh, look who he's with!'" "The whole thing is very odd to me," he added. "I maybe need to grow up or something."

"So the idea of walking down a red carpet is such … you know that forever, I basically stepped into the picture frame of Hollywood," Mayer continued. "For one night, I put on the most amazing suit and entered into the picture frame."

"You have to really be with someone that you know who has your back in that situation, and she did, and it was really great," said Mayer. Asked why he and Aniston decided to make the Oscars their first major public event together, he said, "At some point, you feel comfortable and say this is the choice I want to make."

"I think a year is a pretty good period of time with which to say, 'Let's go have a really good time at the Oscars!'" Before hanging up, Mayer told Seacrest he worried his fans would "misconstrue" his words about Aniston.